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M. Hislop, New species from the Leucopogon pulchellus group
Nuytsia
71
The journal of the Western Australian Herbarium
24: 71–93
Published online 1 May 2014
New species from the Leucopogon pulchellus group (Ericaceae:
Styphelioideae: Styphelieae)
Michael Hislop
Western Australian Herbarium, Department of Parks and Wildlife,
Locked Bag 104, Bentley Delivery Centre, Western Australia 6983
Email: [email protected]
Abstract
Hislop, M. New species from the Leucopogon pulchellus group (Ericaceae: Styphelioideae: Styphelieae).
Nuytsia 24: 71–93 (2014). Five new species and one new subspecies of Leucopogon R.Br. (L. audax
Hislop, L. corymbiformis Hislop, L. darlingensis Hislop, L. decrescens Hislop, L. subsejunctus
Hislop and L. darlingensis subsp. rectus Hislop) are described, illustrated and mapped. Aspects of the
morphology and taxonomy of the informal Leucopogon pulchellus Sond. group are discussed and an
interim key is provided to distinguish between the five informal groups and other unplaced species
of Leucopogon s. str. from Western Australia.
Introduction
The Leucopogon pulchellus Sond. group (or Group C) is one of five informal, subgeneric groups
delineated by Hislop and Chapman (2007) to accommodate the majority of the Western Australian
species of Leucopogon R.Br. s. str. This interim classification was raised in large part to provide a
taxonomic framework into which the many Western Australian taxa then in need of formal descriptions
could be placed. It was considered a better alternative than attempting to utilise Bentham’s (1868)
manifestly artificial classification. The informal groups are based on morphological characters only,
particularly, aspects of their fruiting morphology. Although, as discussed previously (Hislop & Chapman
2007), the L. australis R.Br. group (or Group A) comprises several elements and is best regarded as
one of convenience only, the morphological basis for the integrity of the others is much stronger.
Before any new infrageneric classification can be formalised however, a comprehensive molecular
phylogeny will be needed to test the monophyly of these groups. This should include a broad sample
of the eastern species as well as the several anomalous elements within the western taxa not placed
in the current informal classification.
Earlier papers have provided morphological synopses and keys, published lectotypes where desirable,
and described new taxa for Groups A (Hislop & Chapman 2007; Hislop 2008, 2009a), B (Hislop
2012) and E (Hislop 2009b). The current paper begins the same process for the large L. pulchellus
group (Group C).
Notes on the morphology and taxonomy of the Leucopogon pulchellus group (Group C)
Group C is in large part defined by fruiting characters. The drupe is usually cylindrical or narrowly
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ISSN 2200-2790 (Online)
ISSN 0085-4417 (Print)
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Nuytsia Vol. 24 (2014)
ellipsoid in shape, occasionally narrowly ovoid or narrowly obovoid and often with longitudinal
striations. It is circular to strongly angular or lobed in section. The apex is usually more or less truncate
with angular shoulders, but occasionally the shoulders are rounded or distinctly lobed. The mesocarp is
insignificant, being more or less dry when fresh and with no raised reticulum when dried. A gynophore
is present between the receptacle and the fruiting locules.
In the dried condition the gynophore appears as an area of soft, shiny, translucent tissue, typically
arranged in longitudinal or oblique ridges and grooves (Figure 1) around a narrow axis. It varies in
length and width from rather inconspicuous and stipe-like to well-developed and wider than the body
of the drupe. It seems likely that this structure has a role in fruit dispersal, possibly functioning as an
elaiosome. A gynophore of this kind is also found in members of the L. carinatus R.Br. group as well
as in some of the Leucopogon segregate taxa (i.e. those species currently assigned to the genus but
which occur outside of the Leucopogon s. str. clade, sensu Quinn et al. 2003).
Aside from fruiting characters there is also an inflorescence difference that assists in distinguishing
the members of Group C from those of Group A. Whereas the species of Group A have their upper
leaves and lower fertile bracts clearly dimorphic, in Group C there is a gradual upward transition, at
least on the main axes, from the lowest bracts, which are indistinguishable from the upper leaves, to
the upper bracts which are significantly different in shape and texture (i.e. more ‘bract-like’). There
is a subgroup within Group C (i.e. L. obtusatus Sond. and allied species) that is characterised by
relatively few-flowered inflorescences and very small leaves. In these species there is little difference
between the leaves and any of the fertile bracts. A partial floral difference between Groups A and C
is the absence/presence of an indumentum on the ovary. Whereas ovarian hairs are always lacking
in Group A, they are associated with many species in Group C, including the five described below.
Although the occurrence of such hairs is significant in the taxonomy of the group, it now appears to be
the case that it is rarely, or maybe never, an absolutely consistent character. While most species have a
strong tendency towards having either glabrous or hairy ovaries, it can be expected that plants which
are atypical in this respect are likely to occur, at least within some populations. Furthermore there
are one or two widespread and variable species, such as L. polymorphus Sond. and L. sprengelioides
Sond., in which glabrous or hairy ovaries are more or less equally common. For this reason, within
the group the character is only useful in correlation with others.
Including the five new species published in this paper, Group C comprises 21 named species (Table 1)
with a further eight recognised by phrase names on the census of Western Australian plants. Prior to
this paper the most recent names to be published in the group, L. psammophilus E.Pritz., L. cinereus
E.Pritz. and L. minutifolius W.Fitz. (the latter now considered a taxonomic synonym of L. obtusatus),
appeared in the first decade of the twentieth century. The lack of alpha-taxonomic research since then
has undoubtedly contributed to what might be described as a process of ‘circumscription creep’. This
phenomenon is characterised by an expansion of accepted species concepts to include one or more
morphologically disparate elements. It is commonly encountered where larger genera have not been
subject to recent taxonomic revision. Thus most of the new taxa that are now recognised in Group C
had, through common usage, previously been regarded as variants of earlier-named species.
Group C contains areas of significant taxonomic complexity in which the identification of reliable
morphological characters can be particularly challenging. Even after the recognition of the species
described below, and excluding the remaining phrase-named taxa in the group which are relatively
well-defined, a number of the earlier-named species are still very broadly circumscribed and include
potential segregates. The taxonomic problems arise, in large part, from a general paucity of informative
floral or inflorescence characters. To a degree this also applies within the previously treated groups,
M. Hislop, New species from the Leucopogon pulchellus group
A
73
B
D
C
E
Figure 1. Leucopogon fruit. A – Leucopogon audax; B – L. corymbiformis (arrow indicates gynophore); C – L. darlingensis subsp.
darlingensis (arrow indicates gynophore); D – L. decrescens; E – L. subsejunctus. Scale bars = 1 mm. Drawn by Ellen Hickman
from T. Erickson TEE 204 (A), G.J. Keighery & N. Gibson 5076 (B), F. Hort 2086 (C), M. Hislop 3969 (D), M. Hislop 3962 (E).
but in Group C (and to a greater extent in Group D) it is more likely to be combined with a drupe
morphology which is similarly lacking in taxonomically useful variation. This potentially leads to a
taxonomy in which segregation between taxa is reliant in large part on foliar characters and where
correlating differences in floral or fruiting characters may be only partial. While not necessarily a cause
for concern where such foliar differences are relatively strong and consistent, as for example between
L. pulchellus and L. polymorphus, where the foliar differences are more subtle or show signs of breaking
down, there is an obvious need to proceed with considerable circumspection in seeking to delineate
‘good’ taxa. A molecular study into relationships within the group would be of considerable value
in providing an independent means of interpreting the sometimes problematic morphological signal.
Nuytsia Vol. 24 (2014)
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Table 1. Described species belonging to the Leucopogon pulchellus group (Group C).
Leucopogon assimilis R.Br.
Leucopogon audax Hislop
Leucopogon cinereus E.Pritz.
Leucopogon cordatus Sond.
Leucopogon corymbiformis Hislop
Leucopogon cucullatus R.Br.
Leucopogon darlingensis Hislop
Leucopogon decrescens Hislop
Leucopogon fimbriatus Stschegl.
Leucopogon gracillimus DC.
Leucopogon obtusatus Sond.
Leucopogon oldfieldii Benth.
Leucopogon ozothamnoides Benth.
Leucopogon polymorphus Sond.
Leucopogon polystachyus R.Br.
Leucopogon psammophilus E.Pritz.
Leucopogon pulchellus Sond.
Leucopogon rubricaulis R.Br.
Leucopogon sprengelioides Sond.
Leucopogon stokesii Hislop
Leucopogon subsejunctus Hislop
Methods
This study was based on an examination of dried specimens housed at PERTH together with extensive
field observations of the species described and their putative relatives. Relevant type specimens from
the group were obtained on loan from BM, K and MEL. The distribution map is based on PERTH
specimen data. Foliar measurements were taken from dried specimens. Leaf thickness was measured
at the midrib half way along the lamina. When assessing leaf morphology care should be taken to
confine observations to mature leaves. Inflorescence length was measured from the lowest fertile axil
to the bud rudiment in terminal inflorescences or from the point of attachment at the axil to the bud
rudiment in the case of axillary inflorescences. Floral measurements were taken from rehydrated flowers
in natural posture, with the exception of the corolla lobes which were uncurled to their fullest length
before measuring. The length of the anther sterile tip was measured in late bud or early flower, at or
just before dehiscence. Only the free portions of the filaments were measured. Corolla lobe hair was
measured at a point 0.5 mm below the lobe apex. The given fruit length is inclusive of the gynophore.
At least five flowers per specimen were examined.
Interim key to the informal groups (sensu Hislop & Chapman 2007) and other
anomalous or otherwise unplaced species of Leucopogon s. str. from Western Australia
1. Corolla lobes 0.6–0.8 mm long, internal surfaces of lobes obscurely papillate;
anthers lacking a sterile tip..........................................................................................................L. extremus
1: Corolla lobes at least 1.0 mm long, internal surfaces of lobes bearded,
usually densely so; anthers usually with a sterile tip
2. Anthers straight, lacking a sterile tip
3. Unit inflorescences pendulous, well-separated from each other;
style well-exserted from corolla tube; sepals narrowly ovate,
acute, ± glabrous................................................................................................................L. unilateralis
3: Unit inflorescences erect, densely aggregated into a capitate conflorescence;
style not exserted from corolla tube; sepals very narrowly ovate,
long-acuminate, the upper half terete and densely hairy on all surfaces........................ L. plumuliflorus
2: Anthers always with a ± pale sterile tip, although the tip is sometimes short
and rather inconspicuous, usually ± recurved in the upper half
4. Nectary partite, comprising 5 separate scales
5. Ovary 3–5-locular; corolla lobes usually ± hairy on external surfaces;
M. Hislop, New species from the Leucopogon pulchellus group
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drupe variously shaped, but never as below, an obvious mesocarp usually
present, gynophore absent.................................................................................……………...Group B¹
5: Ovary 2- or 3-locular; corolla lobes glabrous on external surfaces
(except in L. compactus where they may be hairy); drupe narrowly ellipsoid,
narrowly obovoid or cylindrical, without a significant mesocarp,
gynophore present
6. Ovary 2-locular, glabrous (except hairy in a variant of L. glabellus);
drupe apex with smoothly rounded shoulders........................................................................Group D
6: Ovary 2- or 3-locular, hairy, usually with steeply antrorse or
antrorse-appressed hairs; drupe apex truncate,
usually with a narrow rim......................................................................................‘Northern Group’4
4: Nectary entire, truncate to distinctly lobed (but refer to note
under ‘Northern Group’ below)
7. Inner surface of corolla tube with 5 longitudinal inter-staminal
bands of hair extending from the base of the corolla lobes
(except in L. paradoxus where the hairs are reflexed into the
tube from a narrow apical ring); drupe elliptic in section with
2 medial longitudinal grooves, apex a fleshy appendage
± enveloping the style and stigma (except L. paradoxus
which lacks an appendage and has a deciduous style),
endocarp crustaceous...............................................................................................................Group E²
7: Inner surface of corolla tube glabrous, although hairs frequently
reflexed into the tube from the corolla lobe bases; drupe rarely
elliptic in section, without median longitudinal grooves, apex
never with a fleshy appendage, endocarp woody
(except in L. gilbertii)
8. Unit inflorescences short, densely aggregated into a capitate
conflorescence; most leaves on upper axes antrorse-appressed
and stem-clasping; drupe ± dry, obovate in outline, elliptic in
section, endocarp crustaceous.............................................................................................L. gilbertii
8: Character combination not as above
9. Flowers densely arranged along very short inflorescence axes,
the axes shorter than subtending leaves; leaves strongly concave
adaxially, those subtending the inflorescences markedly petiolate
with the lamina sharply inflexed above the petiole; filaments
inserted in the corolla tube well below the sinuses........................... L. oliganthus and allied taxa5
9: Character combination not as above
10. Leaves strongly concave adaxially, densely hairy on the adaxial
surface; at least the lower flowers within the inflorescence
pedicellate below the bracteoles; ovary appressed-hairy in lower
half; drupe without a significant mesocarp, with smoothly
rounded shoulders.................................................................................................... L. navicularis
10: Character combination not as above
11. Drupes depressed-obovoid, depressed-globose, globose or
ellipsoid with an obvious mesocarp present,
apex usually rounded, but if ± flat the shoulders always
smoothly rounded, gynophore absent; upper leaves and
Nuytsia Vol. 24 (2014)
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lower fertile bracts usually clearly dimorphic;
ovary always glabrous...................................................................................................Group A3
11: Drupe cylindrical, narrowly ellipsoid, narrowly ovoid
or narrowly obovoid, without an obvious mesocarp,
apex truncate, usually with ± angular shoulders, occasionally
the shoulders rounded or distinctly lobed, gynophore present;
upper leaves and lower fertile bracts rarely dimorphic on the
main axes, typically grading from one to the other over
several nodes; ovary variously hairy or glabrous...........................................................Group C
For a key to the species of Group B, refer to Hislop (2012).
For a key to the species of Group E, refer to Hislop (2009b).
3
For a key to the species of Group A, refer to Hislop (2009a).
4
The ‘Northern Group’ is a small group of mostly undescribed taxa centred on the Geraldton Sandplains bioregion. While
most of these taxa have a partite nectary, it is entire in the case of L. nitidus Hislop and L. sp. Cataby (F. Hort 1638). The
morphology of the ‘Northern Group’ is discussed in Hislop (2011: 82).
5
Leucopogon oliganthus E.Pritz. together with L. cochlearifolius Strid, L. amplectans Ostenf. and one or maybe two other
undescribed taxa form a small, tightly-knit species group, the wider affinities of which are uncertain.
1
2
Taxonomy
Leucopogon audax Hislop, sp. nov.
Typus: east of Pingelly, Western Australia [precise locality withheld for conservation reasons], 22 August
2010, M. Hislop 4048 (holo: PERTH 08327491; iso: CANB, K, MEL, NSW).
Leucopogon sp. Tutanning (K. Kershaw 2132), Western Australian Herbarium, in FloraBase, http://
florabase.dpaw.wa.gov.au [accessed 11 April 2014].
Erect, open shrubs to c. 150 cm high and 120 cm wide, single-stemmed at ground level with a firesensitive rootstock. Young branchlets with a dense indumentum of straight, ± patent hairs to c. 0.4 mm
long, but mostly < 0.15 mm. Leaves helically arranged, steeply antrorse, narrowly ovate to ovate,
3.5–14 mm long, 2.2–4.7 mm wide; apex acute or subacute; base broad, cuneate to rounded; petiole
very obscure to well-defined, 0.1–0.7 mm long, either shortly hairy throughout or the abaxial surface
glabrous; lamina 0.2–0.3 mm thick, adaxially concave, incurved along the longitudinal axis; surfaces
± concolorous; adaxial surface with a moderately dense or dense indumentum of short, patent hairs,
with 3–5 slightly raised veins usually evident or sometimes the venation very obscure; abaxial surface
glabrous and shiny or more frequently with an indumentum similar to that of the adaxial surface and
with 5–7 slightly sunken to slightly raised veins evident, the midrib rather thicker than the others;
margins either irregularly ciliate with soft hairs to c. 0.5 mm long or ± glabrous. Inflorescences erect,
terminal and upper-axillary; axis 5–18 mm long with 3–13 flowers; axis indumentum of dense,
patent hairs, 0.1–0.3 mm long; flowers erect, sessile or the lowest within an inflorescence shortly
pedicellate below the bracteoles. Fertile bracts narrowly ovate to ovate, acute or subacute. Bracteoles
ovate, 2.0–2.8 mm long, 1.2–1.7 mm wide, acute or subacute, keeled; abaxial surface shortly hairy
throughout, or occasionally towards the base only; margins ciliate. Sepals ovate to narrowly ovate,
3.0–4.0 mm long, 1.5–2.0 mm wide, mostly subacute to acute, occasionally obtuse; abaxial surface
usually shortly, and sparsely to densely hairy throughout, central portion greyish green, suffused
purple towards the apex and in a submarginal band, becoming scarious towards the margins, the
venation usually obscure except for the midvein; margins ciliate with hairs 0.08–0.2 mm long. Corolla
tube white, broadly campanulate, distinctly shorter than sepals, 1.4–1.8 mm long, 1.6–2.1 mm wide,
M. Hislop, New species from the Leucopogon pulchellus group
77
glabrous externally and internally. Corolla lobes white or partially flushed pink, much longer than the
tube (ratio = 2.0–2.9: 1), widely spreading from the base and recurved, 3.5–4.4 mm long, 1.0–1.2 mm
wide at base, glabrous externally (or very occasionally sparsely hairy), densely bearded internally;
indumentum white, 1.0–1.4 mm long near apex. Anthers partially exserted from tube (by c. 3/4 of
their length), 2.1–2.7 mm long, prominently recurved towards the apex; sterile tip conspicuous, white,
0.8–1.2 mm long. Filaments terete, 0.9–1.2 mm long, attached 1/2–2/3 above anther base, adnate
to tube just below the sinuses. Ovary depressed-globose or depressed-obovoid, 0.7–1.0 mm long,
0.8–1.1 mm wide, densely hairy in the lower half, glabrous above, (4)5-locular. Style 0.6–0.9 mm long,
abruptly differentiated from the ovary apex, included within the corolla tube; stigma not or scarcely
expanded. Nectary annular, 0.3–0.5 mm long, entire or very shallowly lobed, glabrous. Fruit longer
than the calyx, 3.7–4.4 mm long, 2.3–2.6 mm wide, cylindrical, hairy over most of its surface with a
spreading indumentum, prominently grooved longitudinally; apex truncate, the shoulders ± rounded;
surface between the shoulder and the style base descending steeply; style persistent but concealed at
maturity in a depression created by the steeply descending surface of the fruit apex. (Figures 1A, 2)
Diagnostic characters. Within the L. pulchellus group L. audax can be distinguished by the following
character combination: a grey-hairy aspect; leaves adaxially concave and relatively broad (2.2–4.7 mm
wide); at least the adaxial surface, but usually both surfaces, densely hairy with short, patent hairs;
the abaxial surface more or less smooth to broadly and faintly grooved; relatively large floral parts
(e.g. sepals 3.0–4.0 mm long and 1.5–2.0 mm wide) and fruit (i.e. 3.7–4.4 mm long and 2.3–2.6 mm
wide); a densely hairy, (4)5-locular ovary.
Other specimens examined. WESTERN AUSTRALIA: [localities withheld for conservation reasons]
21 Aug. 1986, A.R. Chapman 333, J.M. Powell & A.J.G. Wilson (NSW, PERTH); 1 Nov. 2007,
T. Erickson TEE 204 (K, PERTH); 15 Sep. 1984, D.B. Foreman 719 (MEL, NSW, PERTH); 10 Oct.
1998, A.G. Gunness et al. NYAM 9/05 (PERTH); 5 Nov. 1998, A.G. Gunness et al. NYAM 13/09
(PERTH); 8 Sep. 2002, M. Hislop 2754 (CANB, MEL, NSW, PERTH); 22 Aug. 2010, M. Hislop 4046
(CANB, K, NSW, PERTH); 22 Aug. 2010, M. Hislop 4047 (CANB, PERTH); 26 Aug. 2005, F. Hort &
J. Hort FH 2597 (CANB, PERTH); 31 Aug. 1997, G.J. Keighery & N. Gibson 5601 (CANB, PERTH);
9 Oct. 2000, K. Kershaw 2132 (NSW, PERTH); 17 Dec. 1965, P.G. Wilson 3946 (MEL, PERTH).
Distribution and habitat. Leucopogon audax has a restricted distribution in the Brookton–Pingelly
district (Figure 3) in the west of the Avon Wheatbelt bioregion (Department of the Environment,
Water, Heritage and the Arts 2008). It occurs mostly on lateritic, upland sites (one collection records it
growing over a granitic substrate) in heath or open Eucalyptus accedens or E. drummondii woodland.
Phenology. The main flowering period is between August and October. Fruiting collections have been
made in November and December.
Etymology. From the Latin audax (bold), an oblique reference to the tall habit and conspicuous, large
flowers of the new species.
Conservation status. Department of Parks and Wildlife Conservation Codes for Western Australian
Flora: Priority Two (Smith 2013), as L. sp. Tutanning (K. Kershaw 2132). Leucopogon audax is a
short-range endemic currently known to occur in two nature reserves. The other populations are on
private property.
Affinities. Within its limited geographical range L. audax is unlikely to be confused with other members
Nuytsia Vol. 24 (2014)
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Figure 2. Leucopogon audax. Photograph of flowering branchlet
from M. Hislop 4046. Scale bar = 2 cm.
of the genus, although another two species from the L. pulchellus group, L. oldfieldii Benth. and
L. darlingensis Hislop (described below), often share a similar grey-hairy aspect. The distribution of
L. darlingensis approaches that of L. audax closely to the west, but there are no records of the two
occurring in sympatry. Foliar characters provide the most obvious means by which the two can be
distinguished from one another. Leucopogon darlingensis has leaves with recurved or revolute margins
and an abaxial surface that is grooved between the raised veins whereas in L. audax the leaves are
flat or concave adaxially and more or less smooth abaxially. The very variable L. oldfieldii of the
Geraldton Sandplains bioregion usually has a 3(4)-locular ovary, longer ovarian hairs and leaves
which are usually deeply grooved abaxially.
Leucopogon corymbiformis Hislop, sp. nov.
Typus: Cape Arid National Park, Western Australia [precise locality withheld for conservation reasons],
20 August 2012, M. Hislop 4227 (holo: PERTH 08382093; iso: CANB, K, MEL, NSW).
M. Hislop, New species from the Leucopogon pulchellus group
79
Figure 3. Distribution of Leucopogon audax (), L. corymbiformis (), L. darlingensis subsp. darlingensis (), L. darlingensis
subsp. rectus (), L. decrescens () and L. subsejunctus () in Western Australia.
Leucopogon sp. Cape Arid (M. Paxman 50), Western Australian Herbarium, in FloraBase, http://
florabase.dpaw.wa.gov.au [accessed 11 April 2014].
Erect shrubs to c. 70 cm high and 70 cm wide, but usually less, single-stemmed at ground level with
a fire-sensitive rootstock. Young branchlets glabrous. Leaves helically arranged, antrorse, usually
steeply so, mostly narrowly elliptic to narrowly obovate, occasionally narrowly ovate, 3.0–7.5 mm
long, 1.0–1.8 mm wide; apex usually acute or subacute, occasionally obtuse; base attenuate to cuneate;
petiole usually well-defined, 0.3–0.8 mm long, glabrous on abaxial surface and margins, shortly and
sparsely hairy on the adaxial surface; lamina 0.20–0.35 mm thick, usually convex adaxially, less often
flat or slightly concave, ± straight or incurved along the longitudinal axis; surfaces ± concolorous;
adaxial surface glabrous or very sparsely hairy towards the base, the venation not evident; abaxial
surface glabrous, with 3–5 raised primary veins and distinct grooves between, the midrib rather
thicker than the others; margins glabrous or coarsely ciliolate, at least in the upper half, with antrorse
hairs to c. 0.08 mm long. Inflorescence erect, terminal and upper-axillary; axis glabrous, 4–9 mm
long with 3–12 flowers; flowers erect and pedicellate below the bracteoles for 0.8–3.0 mm. Fertile
bracts narrowly ovate, acute. Bracteoles ovate, 1.1–1.5 mm long, 0.8–1.0 mm wide, obtuse to acute,
keeled; abaxial surface glabrous, often ± papillose; margins ciliolate. Sepals narrowly ovate to ovate,
1.6–2.5 mm long, 0.7–1.1 mm wide, subacute or obtuse and then usually minutely apiculate; abaxial
surface mostly glabrous and ± papillose, sometimes very shortly hairy, central portion green or grey
± suffused purple towards the apex and in a submarginal band, becoming scarious towards the margins,
the venation usually rather prominent with 3–5 veins evident towards the apex; margins ciliate with
hairs 0.05–0.15 mm long. Corolla tube white, campanulate, shorter than the sepals, 1.2–1.6 mm long,
1.2–1.4 mm wide, glabrous externally and internally. Corolla lobes white, sometimes partially flushed
pink, longer than the tube (ratio = 1.3–1.8: 1), widely spreading from the base and recurved, 1.8–2.4 mm
long, 0.6–0.9 mm wide at base, glabrous externally, densely bearded internally; indumentum white,
0.6–0.8 mm long near apex. Anthers partially exserted from the tube (by 1/2–2/3 of their length),
1.2–1.5 mm long, rather shallowly recurved towards apex; sterile tip moderately conspicuous, pale,
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Nuytsia Vol. 24 (2014)
0.4–0.6 mm long. Filaments terete, 0.3–0.5 mm long, attached 1/2–2/3 above anther base, adnate to
tube just below sinuses. Ovary globose, 0.45–0.55 mm long, 0.45–0.55 mm wide, obscurely lobed,
glabrous, except for six short, longitudinal bands or tufts of hair, occasionally entirely glabrous,
3(4)-locular. Style 0.4–0.6 mm long, tapering smoothly from ovary apex, included within corolla
tube; stigma not or scarcely expanded. Nectary annular, 0.3–0.4 mm long, entire or shallowly lobed,
glabrous. Fruit much longer than calyx, 2.5–3.0 mm long, 1.1–1.3 mm wide, shortly cylindrical or
obovoid, deeply lobed with lobes that are well-separated in the distal half but ± converge towards the
base, shortly hairy in two longitudinal bands along the lateral surfaces of each lobe (but presumably
sometimes entirely glabrous); surface between the lobes and the style base descending steeply; style
persistent. (Figure 1B, 4)
Diagnostic characters. Within the L. pulchellus group, L. corymbiformis can be distinguished by the
following character combination: glabrous inflorescence axes; pedicellate flowers; deeply lobed fruit.
Other specimens examined. WESTERN AUSTRALIA: [localities withheld for conservation reasons]
9 Sep. 1966, E.M. Bennett 809 (PERTH); 10 May 2004, D.J. Edinger & G. Marsh DJE 4108 (PERTH);
1 Sep. 1962, C.A. Gardner 14112 (PERTH); 20 Aug. 2012, M. Hislop 4226 (CANB, MEL, NSW,
PERTH); 20 Aug. 2012, M. Hislop 4228 (CANB, NSW, PERTH); 12 Oct. 2000, G.J. Keighery &
N. Gibson 5076 (PERTH); 11 Aug. 1993, M. Paxman 50 (PERTH); 18 July 1982, J.M. Powell 1849B
(CANB, K, NSW, PERTH); 11 Aug. 2006, C.D. Turley 21/806 (CANB, NSW, PERTH); 11 Aug. 2006,
C.D. Turley 124/806 (CANB, PERTH); 12 Sep. 1964, P.G. Wilson 3031 (AD, PERTH).
Distribution and habitat. This species has an apparently disjunct distribution within the Esperance
Plains bioregion (Department of the Environment, Water, Heritage and the Arts 2008). Apart from an
old collection with the vague locality of ‘Esperance’ all specimens at the Western Australian Herbarium
were either collected from an area about 20 to 30 km north of Esperance or from Cape Arid National
Park (Figure 3). There is also an unvouchered record from the Mount Merivale area about 20 km
east of Esperance (W. Archer pers. comm.). Leucopogon corymbiformis grows on sandplain or subcoastal dunes in Banksia woodland or heath. Commonly associated species include Banksia speciosa,
Adenanthos cuneatus, Melaleuca striata, M. scabra and Agonis baxteri.
Phenology. The main flowering period is between July and September. The only specimen with mature
fruit was collected in the second week of October.
Etymology. From the Latin corymbus (a cluster of flowers) and -formis (-formed); having an inflorescence
with the general appearance of, but not necessarily the structure of, a true corymb. This is a reference
to the inflorescence of this species which is an unusual one for the genus, in that the flowers are
pedicellate with the pedicels becoming progressively shorter towards the top of the inflorescence.
Conservation status. Department of Parks and Wildlife Conservation Codes for Western Australian
Flora: recently listed as Priority Two under the name L. sp. Cape Arid (M. Paxman 50) (Western
Australian Herbarium 1998–). There is still some doubt at this stage whether the apparent disjunction
in the range of this species is real or an artifact of inadequate collecting between Esperance and Cape
Arid. The recent unvouchered record from south of Mount Merivale may be an indication that it is
the latter, however the fact that there are no records from the generally well-collected Cape Le Grand
National Park is probably significant and even at Cape Arid National Park its distribution appears to
be rather patchy.
Affinities. This is a distinctive, uniform species the closer affinities of which are problematic. It is
M. Hislop, New species from the Leucopogon pulchellus group
81
Figure 4. Leucopogon corymbiformis. Photograph of flowering
branchlet from M. Hislop 4226. Scale bar = 2 cm.
easily recognised by three unusual characters: clearly pedicellate flowers, distinctively lobed fruit and
glabrous inflorescence axes. Although L. subsejunctus Hislop is similar in having a lobed fruit, it has the
lobes separated by deep, narrow grooves for the entire length of the drupe whereas in L. corymbiformis
the lobes are widely separated in the distal half and converge toward the base. This, together with the
other unusual features of L. corymbiformis mentioned above, which are absent from L. subsejunctus,
suggests that the two are unlikely to be particularly close relatives.
Leucopogon darlingensis Hislop, sp. nov.
Typus: Wills Nature Reserve, Bartram Road, Brookton, 3.9 km north of Brookton Highway or 100 m
south of Wills Road, Western Australia, 24 September 2005, F. & J. Hort 2618 (holo: PERTH 07189613;
iso: CANB, NSW).
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Nuytsia Vol. 24 (2014)
Leucopogon sp. Darling Range (F. & J. Hort 1804), Western Australian Herbarium, in FloraBase,
http://florabase.dpaw.wa.gov.au [accessed 11 April 2014].
Erect shrubs to c. 1.2 m high and 1.5 m wide, single or multi-stemmed at ground level and at least
sometimes with a fire-tolerant rootstock. Young branchlets with a moderately dense to dense indumentum,
comprising either uniformly crisped hairs, uniformly straight hairs or a mixture of crisped and ± straight
hairs, the longest to c. 0.5 mm long. Leaves helically arranged, usually variously antrorse, occasionally
patent to shallowly retrorse, linear, oblong, narrowly elliptic or narrowly ovate, 5–18 mm long,
0.7–3.5 mm wide; apex acute to subacute; base attenuate; petiole obscure to moderately well-defined,
0.3–0.8 mm long, hairy throughout; lamina 0.3–0.5 mm thick, curvature variable, adaxial surface
convex with the margins varying from slightly recurved with the abaxial surface visible throughout
to revolute and with the abaxial surface completely concealed, longitudinal axis ± incurved in the
upper half, less often straight; surfaces discolorous; adaxial surface shiny, sparsely to densely hairy
with curved or crisped hairs, sometimes glabrescent, the venation not evident; abaxial surface shiny
or not, usually moderately to densely hairy (occasionally sparsely hairy only), with 3–7 primary veins,
grooved, often deeply so, between the veins, the midrib distinctly thicker than the others; margins
usually irregularly ciliate, with hairs to c. 1 mm long, less often ± glabrous. Inflorescence erect,
terminal and upper-axillary; axis 6–12 mm long with 2–10 flowers; axis indumentum dense, of crisped
and straight hairs, 0.1–0.3 mm long; flowers erect and sessile. Fertile bracts narrowly ovate, acute.
Bracteoles ovate to narrowly ovate, 1.1–3.2 mm long, 0.9–1.8 mm wide, acute or acuminate, keeled;
abaxial surface hairy throughout; margins ciliate. Sepals ovate to narrowly ovate, 2.4–4.2 mm long,
1.1–2.0 mm wide, acute, subacute or obtuse; abaxial surface variously hairy throughout, central portion
pale green, ± suffused purple towards the apex and in a submarginal band, becoming scarious towards
the margins at least in the lower half, the midrib often prominent, the other venation obscure; margins
ciliate with hairs 0.08–0.50 mm long. Corolla tube white, broadly campanulate, much shorter than the
sepals, 1.1–2.0 mm long, 1.1–2.2 mm wide, glabrous externally and internally. Corolla lobes white,
much longer than tube (ratio = 2–3.5: 1), widely spreading from base and recurved, 3.0–4.7 mm long,
0.7–1.2 mm wide at base, glabrous externally or very occasionally sparsely hairy, densely bearded
internally; indumentum white, 1.0–1.4 mm long near apex. Anthers partially exserted from tube (by
3/4–7/8 of their length), 1.7–3.1 mm long, prominently recurved towards the apex; sterile tip conspicuous,
white, 0.6–1.0 mm long. Filaments terete, 0.5–1.5 mm long, attached 1/2–2/3 above anther base, adnate
to tube just below sinuses. Ovary ellipsoid to globose, 0.7–1.0 mm long, 0.6–0.8 mm wide, usually
appressed-hairy in the lower half, occasionally glabrous, (4)5-locular. Style 0.4–1.0 mm long, usually
well-differentiated from ovary apex, included within corolla tube; stigma not or scarcely expanded.
Nectary annular, 0.3–0.5 mm long, shallowly lobed, glabrous, sometimes completely enveloping the
ovary. Fruit usually distinctly longer than, but occasionally ± equal to, the calyx, 3.2–4.2 mm long,
1.6–2.0 mm wide, cylindrical or narrowly ellipsoid, usually variously hairy, occasionally glabrous,
usually longitudinally grooved; apex truncate, the shoulders angular to ± rounded; surface between
the shoulder and the style base flat or descending gently; style usually persistent.
Diagnostic characters. Within the L. pulchellus group, L. darlingensis can be distinguished by the
following character combination: a usually grey-hairy aspect; narrow adaxially convex leaves with
recurved to revolute margins; at least the abaxial surface, but usually both surfaces, variously hairy;
the abaxial surface grooved; a usually hairy (occasionally glabrous), (4)5-locular ovary.
Etymology. The species is named for its occurrence in the Darling Range.
Affinities. The only other described species from Group C that has prominently recurved to revolute
leaf margins is L. rubricaulis R.Br. from southern near-coastal districts between Cheyne Beach and
M. Hislop, New species from the Leucopogon pulchellus group
83
Broke Inlet. That species is easily distinguished by its more or less smooth, usually glabrous abaxial
leaf surfaces (grooved and always hairy in L. darlingensis) and sepals that are glabrous or very
shortly hairy and obtuse or subacute (cf. always hairy, usually densely so and acute to subacute). In
addition, the ovarian hairs in L. rubricaulis are always very short and restricted to the apex whereas
in L. darlingensis the hairs begin some way below the apex and are usually longer.
Notes. The German botanist Alfred Meebold apparently made the first collection of this species in June
of 1933. However it may well be that the ‘Parkerville’ locality given for that specimen is approximate
only. All subsequent collections have been made well to the south and east of the Parkerville area.
Two apparently allopatric subspecies are recognised, based on indumentum and minor floral differences.
Key to subspecies of Leucopogon darlingensis
1. Branchlet and foliar indumentum composed of uniformly crisped hairs,
or of a mixture of crisped and ± straight hairs; marginal hairs crinkled at least in
upper half of sepals; corolla lobe width 0.9–1.2 mm; filaments
0.9–1.5 mm long (SW of York south to North Bannister and Wandering)..................... subsp. darlingensis
1: Branchlet and foliar indumentum composed of ± straight hairs only;
sepal marginal hairs straight throughout; corolla lobe width 0.7–1.0 mm;
filaments 0.5–1.0 mm long (Dryandra Woodland–Williams–Highbury).................................. subsp. rectus
Leucopogon darlingensis Hislop subsp. darlingensis
Young branchlets either with a uniform indumentum of crisped hairs or a mixture of crisped and
± straight hairs. Leaves 0.7–2.0 mm wide; both surfaces sparsely to densely hairy, either with crisped
hairs throughout or a mixture of crisped and ± straight hairs. Sepals 1.4–2.0 mm wide, the margins
ciliate with crinkled hairs throughout or at least in the upper half. Corolla lobes 0.9–1.2 mm at base.
Filaments 0.9–1.5 mm long. (Figure 1C, 5)
Other specimens examined. WESTERN AUSTRALIA: Dale West Rd, 1.3 km E of Brookton Hwy,
NW of Brookton, 3 Sep. 2000, M. Hislop 2121 (CANB, PERTH); base of SW slopes of Mt Cooke,
28 Aug. 2004, M. Hislop 3306 (CANB, PERTH); [Woodland Watch] site 235, [private property] W side
of Hillcroft Rd between Dale Rd South and Groves Rd, W of Brookton, 1 Sep. 2008, M. Hislop &
M. Griffiths WW 235-8 (MEL, NSW, PERTH); [Woodland Watch] site 236, [private property] E side of
Butchers Rd between Vallentine and Wills Rds, W of Brookton, 1 Sep. 2008, M. Hislop & M. Griffiths
WW 236-9 (CANB, PERTH); SW of junction of Watershed Rd and McCallum Rd, Gibbs State Forest,
Shire of Wandering, 29 July 1999, F. Hort 526 (CANB, NSW, PERTH); Wandoo Conservation Park,
S of Dale West Rd, Shire of Beverley, [Dale West Rd 5.8 km E of Dobaderry Rd then SW along forest
E boundary], 5 Aug. 1999, F. Hort 528 (NSW, PERTH); Canning River Rd, Wandering: 1.3 km S of
Millars Log Rd – E of Mt Cooke, 21 Aug. 2002, F. & J. Hort 1804 (CANB, MEL, NSW, PERTH);
Gunapin Ridge, Qualen Rd, York, 25 Aug. 2003, F. Hort 1999 (MEL, PERTH); proposed Wandoo
National Park, Catchment Rd, Beverley. On hilltop and N slopes c. 5.8 km N of Dobaderry Rd, 11 Sep.
2003, F. Hort & G. Harders 2032 (K, PERTH); Reserve 4328, Rigoll Rd Beverley, 2.4 km SSE of
Dobaderry Rd, 11 Sep. 2003, F. Hort 2034 (CANB, PERTH); Edison Mill Rd, Beverley, c. 5.5 km E
of Dobaderry Rd then S along the E boundary of the proposed Wandoo National Park, c. 1 km from
the SE corner of the park, 11 Sep. 2003, F. Hort 2036 (NSW, PERTH); Gibbs State Forest, Metro Rd,
Wandering: 3 km S of Division Track, 6 Nov. 2003, F. Hort 2086 (CANB, NSW, PERTH); Lupton
Conservation Park, Brookton, from Perimeter Rd at SW corner of PP Loc. 16674 ENE along boundary
Nuytsia Vol. 24 (2014)
84
Figure 5. Leucopogon darlingensis subsp. darlingensis. Photograph of
flowering branchlet from F. Hort 526. Scale bar = 2 cm.
track for 2.9 km then 200 m SE, 10 Aug. 2005, F. Hort 2552 (MEL, PERTH); Albany Hwy, Wandering,
W side of Hwy 1.1 km S of Pike Rd, 10 Sep. 2005, F. & J. Hort 2615 (CANB, PERTH); Wearne State
Forest, Ricks Rd, 2.5 km directly WNW from the junction with Heartbreak Rd, Wandering, 28 Aug.
2010, F. & J. Hort 3687 (CANB, MEL, PERTH); near North-East Rd, 7.3 km of Muja powerline
crossing [NW of North Bannister], 10 Aug. 1993, K. McDougall 219 (PERTH).
Distribution and habitat. Apparently endemic to the eastern Darling Range, extending from southwest of York to the North Bannister and Wandering areas (Figure 3) in the Northern Jarrah Forest and
western edge of the Avon Wheatbelt bioregions (Department of the Environment, Water, Heritage
and the Arts 2008). Occurs in sandy or light loam soils, on lateritic uplands, and in association with
woodlands dominated by Eucalyptus marginata, E. wandoo, E. accedens and Corymbia calophylla.
M. Hislop, New species from the Leucopogon pulchellus group
85
Phenology. Peak flowering is in August and September. Fruiting collections have been made in
October and November.
Conservation status. Although not having a particularly wide distribution, it is a locally common plant
in a part of the state which is still, in large part, covered in natural vegetation. It is well represented
in the reserve system with most of the other populations in state forest. No conservation coding is
recommended here.
Leucopogon darlingensis Hislop subsp. rectus Hislop, subsp. nov.
Typus: Dryandra Woodland, north-west of Narrogin, Western Australia [precise locality withheld for
conservation reasons], 23 August 2012, M. Hislop 4235 (holo: PERTH 08549915; iso: CANB, K,
MEL, NSW).
Young branchlets with an indumentum of ± straight hairs only, these often of mixed lengths. Leaves
1.0–3.5 mm wide; both surfaces usually densely hairy with ± straight hairs. Sepals 1.1–1.6 mm
wide, the margins ciliate with straight hairs throughout. Corolla lobes 0.7–1.0 mm at base. Filaments
0.5–1.0 mm long.
Diagnostic characters. Distinguished from the typical subspecies by its uniformly straight hairs on
branchlets, leaves and sepal margins, generally narrower sepals and corolla lobes and shorter filaments.
Other specimens examined. WESTERN AUSTRALIA: [localities withheld for conservation reasons]
8 Sep. 2001, J. Foss & P. Gurry 53 (PERTH); 24 Oct. 1991, W. Greuter 23196 (PERTH); 22 Aug. 2012,
M. Hislop 4232 (CANB, NSW, PERTH); 22 Aug. 2012, M. Hislop 4233 (CANB, PERTH); 23 Aug.
2012, M. Hislop 4234 (NSW, PERTH); 18 Sep. 2012, M. Hislop 4240 (CANB, NSW, PERTH); 6 Oct.
2013, M. Hislop 4288 (CANB, NSW, PERTH); 11 Aug. 2004, F. Hort & B. Hort 2293 (CANB, NSW,
PERTH); 8 Sep. 1983, G.J. Keighery 6572 (PERTH); 2 Oct. 1994, T.R. Lally 400 (CANB, PERTH);
5 Aug. 1987, D. Rose 90 (PERTH); 9 Aug. 1999, G. Warren, C. Taylor & P. Rose 272 (PERTH);
15 Sep. 2000, G. Warren & P. Rose 272B (PERTH).
Distribution and habitat. This taxon has a restricted distribution between Williams, Dryandra Woodland
and the Highbury area (Figure 3) in the Avon Wheatbelt and eastern edge of the Northern Jarrah Forest
bioregions (Department of the Environment, Water, Heritage and the Arts 2008). Its favoured habitat
of open woodland on lateritic uplands is very much the same as that of the typical subspecies and
indeed is a common one for species across Group C.
Phenology. As for the typical subspecies.
Etymology. From the Latin rectus (straight), referring to the straight hairs of the branchlets, leaves
and sepals of this taxon.
Conservation status. Department of Parks and Wildlife Conservation Codes for Western Australian
Flora: to be listed as Priority Two (A. Jones pers. comm.). Leucopogon darlingensis subsp. rectus is
locally common across its restricted range and most populations are conserved in nature reserves or
state forest.
Notes. The two subspecies of L. darlingensis are presumed to be allopatric. The closest that they
86
Nuytsia Vol. 24 (2014)
are known to approach each other is about 40 km. Two specimens collected from west of Bannister
(J. Freeman JF 007 and T. Laslett TL 189), a little to the south of the known distribution of the typical
subspecies, do not well fit within this infraspecific classification. The vegetative indumentum is like
that of subsp. rectus however the sepal indumentum is more similar to that of the typical subspecies.
The abaxial leaf surface is unusual for the species as a whole, in having very few hairs and in being
unusually broadly and shallowly grooved. The diagnostic floral characters are intermediate between
the two. Although this population in some ways blurs the boundaries between the two subspecies,
L. darlingensis is a well collected species and the large specimen base is otherwise supportive of the
recognition of two taxa.
Leucopogon decrescens Hislop, sp. nov.
Typus: south side of Muirs Highway, 1.1 km west of Perillup Road, east of Rocky Gully, Western
Australia, 24 August 2008, M. Hislop 3820 (holo: PERTH 08083223; iso: CANB, MEL, NSW).
Leucopogon sp. Darradup (R.D. Royce 2998), Western Australian Herbarium, in FloraBase, http://
florabase.dpaw.wa.gov.au [accessed 11 April 2014]; G. Paczkowska & A.R. Chapman, West. Aust.
Fl.: Descr. Cat.: 240 (2000); J. Wheeler, N. Marchant & M. Lewington, Fl. South West 2: 600 (2002).
Erect, open shrubs to c. 70 cm high and 70 cm wide, single-stemmed at ground level with a firesensitive rootstock. Young branchlets with a variable indumentum of straight, curled and/or crisped
hairs to c. 0.5 mm long. Leaves helically arranged, steeply antrorse to antrorse-appressed, usually
narrowly ovate, less often ovate, 2.0–7.2 mm long, 0.9–1.6 mm wide; apex variable, usually acute
or subacute, occasionally acuminate or obtuse; base broad, cuneate; petiole ± absent or to c. 0.2 mm
long, if present then usually hairy to some degree; lamina 0.15–0.25 mm thick, concave adaxially,
incurved along the longitudinal axis; surfaces ± concolorous; adaxial surface with a moderately dense
to dense indumentum of mostly straight, patent to antrorse hairs, the venation obscured by hairs; abaxial
surface with a sparse to moderately dense indumentum, which sometimes becomes abraded on older
leaves leaving the surface verrucose, or occasionally glabrous, with 5–7 primary veins, these usually
flat or occasionally slightly raised causing the surface to be shallowly grooved between the veins, the
midrib thicker than the others; margins irregularly ciliate with hairs to 0.5 mm long. Inflorescence
erect, terminal and upper-axillary; axis 4–10 mm long with 4–11 flowers; axis indumentum of dense
patent to shallowly antrorse hairs 0.2–0.5 mm long; flowers erect and sessile. Fertile bracts narrowly
ovate, acute. Bracteoles narrowly ovate, 1.5–2.5 mm long, 0.8–1.0 mm wide, acute to acuminate,
sharply keeled; abaxial surface with spreading hairs; margins ciliate. Sepals ovate or narrowly ovate,
2.3–3.0 mm long, 1.0–1.4 mm wide, acute, subacute or obtuse; abaxial surface usually hairy in the
upper half with an indumentum of loose, antrorse hairs, or very occasionally ± glabrous, central
portion pale greyish green, suffused purple in the upper half, becoming scarious towards the margins,
the venation rather obscure with only the midrib evident; margins ciliate with hairs 0.1–0.4 mm long.
Corolla tube white, campanulate or broadly campanulate, distinctly shorter than sepals, 1.2–1.7 mm
long, 1.2–1.5 mm wide, glabrous externally and internally. Corolla lobes white throughout, or more
often partially flushed pink, longer than the tube (ratio = 1.3–2.6: 1), widely spreading from the base and
recurved, 2.0–3.2 mm long, 0.7–0.8 mm wide at base, glabrous externally, densely bearded internally;
indumentum white, 0.8–1.2 mm long near apex. Anthers partially exserted from tube (by 3/4–7/8 of
their length), 1.5–2.0 mm long, prominently recurved towards the apex; sterile tip conspicuous, white,
0.4–0.6 mm long. Filaments terete, 0.5–0.9 mm long, attached 2/3–3/4 above anther base, adnate
to tube just below the sinuses. Ovary globose or depressed-globose, 0.5–0.7 mm long, 0.6–0.8 mm
wide, usually appressed-hairy, or very occasionally glabrous, (3)4–5-locular. Style 0.4–0.7 mm long,
usually well-differentiated from ovary apex, included within the corolla tube; stigma not or scarcely
M. Hislop, New species from the Leucopogon pulchellus group
87
expanded. Nectary annular, 0.25–0.40 mm long, entire to shallowly lobed, glabrous. Fruit about the
same length to somewhat longer than the calyx, 1.8–2.8 mm long, 1.2–1.7 mm wide, shortly cylindrical,
from slightly to distinctly angular in section, usually rather densely hairy, very occasionally glabrous;
apex truncate with angular shoulders; surface between the rim and the style base flat or descending
gently; style persistent. (Figures 1D, 6)
Diagnostic characters. Within the L. pulchellus group, L. decrescens can be distinguished by the
following character combination: leaves adaxially concave and incurved, steeply antrorse to antrorseappressed, usually narrowly ovate (0.9–1.6 mm wide); the adaxial surface hairy, usually densely so,
with a variable indumentum of patent to antrorse hairs; the abaxial surface more or less smooth to
broadly and faintly grooved; a usually densely hairy, (3)4- or 5-locular ovary (1.8–3.0 mm long and
1.2–1.7 mm wide).
Other specimens examined. WESTERN AUSTRALIA: Corbalup Rd, 700 m N of Seaton Ross Rd [E
of Manjimup], 15 Sep. 1993, A.R. Annels ARA 3670 (NSW, PERTH); Lake Unicup, 13 Aug. 1999,
R.J. Cranfield 13834 (PERTH); Boarding House Rd, 4.3 km N of Mowen Rd, W of Nannup, 26 Nov.
2006, M. Hislop 3684 (CANB, NSW, PERTH); N side of Wingebellup Rd, 6.6 km E of Mordalup
Rd, W of Frankland, 23 Aug. 2008, M. Hislop 3818 (CANB, NSW, PERTH); S side of Muirs Hwy,
1.1 km W of Perillup Rd, E of Rocky Gully, 14 Nov. 2009, M. Hislop 3969 (CANB, NSW, PERTH);
Northern Rd, 9.8 km N of Mordalup Rd, SE of Manjimup, 15 Nov. 2009, M. Hislop 3984 (CANB,
NSW, PERTH); Galamup Nature Reserve, W of Rocky Gully between Muirs Hwy and first internal
firebreak, 12 Sep. 2010, M. Hislop 4068 (CANB, MEL, PERTH); Lake Muir Nature Reserve, Muirs
Hwy, 2.9 km E of Nabacup Rd, W of Rocky Gully, 12 Sep. 2010, M. Hislop 4069 (CANB, MEL,
NSW, PERTH); NE corner of Kulunilup Nature Reserve, off Wingebellup Rd, 2.5 km E of Unicup
Rd, NW of Frankland, 13 Sep. 2010, M. Hislop 4072 (CANB, MEL, NSW, PERTH); Galamup Nature
Reserve [W of Rocky Gully], 23 Oct. 1997, G.J. Keighery & N. Gibson 2352 (PERTH); Manjimup,
24 Oct. 1947, R.D. Royce 2361 (NSW, PERTH); Manjimup, 28 Sep. 1948, R.D. Royce 2727 (NSW,
PERTH); 18 miles [c. 29 km] W of Nannup, 29 Oct. 1948, R.D. Royce 2998 (PERTH); c. 200 m S on
creekline (S side), c. 2 km E of Stoate Rd on Mowen Rd [W of Nannup], 7 Sep. 2000, L.W. Sage &
A.E. Raudino 2376 (CANB, PERTH); remnant bushland NW of corner Hay Loc. 2043, ITC Spring
Valley Farm, c. 5.2 km SE of Muirs Bridge, Muirs Hwy, 14 Nov. 2003, E.M. Sandiford EMS 940
(PERTH).
Distribution and habitat. Leucopogon decrescens is distributed in a rather narrow east-west band
from the Whicher Range in the west to between Rocky Gully and Mount Barker in the east (Figure
3). This places it in the Southern Jarrah Forest bioregion (Department of the Environment, Water,
Heritage and the Arts 2008). It grows on sandy soils, very occasionally over laterite or granite, low in
the landscape and often close to winter-wet sites. Associated vegetation is woodland or heath with the
following species frequently dominant: Eucalyptus decipiens, E. marginata, Melaleuca preissiana,
M. thymoides, Banksia attenuata, B. littoralis, Pericalymma ellipticum and Taxandria parviceps.
Phenology. Peak flowering is during the months of August and September, with maximum fruiting
between October and November.
Etymology. From the Latin decrescens (diminishing, narrowing), in reference to the outline of the
narrowly ovate leaves which in their typical form taper more or less smoothly from the widest point
in the basal half to the acute apex. This highlights an often useful character which helps to distinguish
it from related species.
Nuytsia Vol. 24 (2014)
88
Figure 6. Leucopogon decrescens. Photograph of flowering branchlet
from M. Hislop 3820. Scale bar = 2 cm.
Conservation status. Leucopogon decrescens has a fairly wide regional distribution, is often locally
common and is represented in a number of nature reserves. No conservation coding is recommended here.
Affinities. Older collections of this species have mostly been referred to L. pulchellus or L. polymorphus,
and the latter is the most similar to L. decrescens in terms of its gross morphology. Reliable foliar
differences provide the best means of distinguishing between the two. In L. polymorphus the leaves
vary between narrowly ovate, narrowly elliptic and sometimes obovate (commonly even on the same
plant), the abaxial leaf surface is deeply grooved and although both surfaces vary from conspicuously
hairy to more or less glabrous, if they are obviously hairy then the adaxial surface is no more densely
so than the abaxial. Leucopogon decrescens differs from this in mostly having narrowly ovate leaves
(rarely ovate), with a smooth or occasionally shallowly grooved abaxial surface and a consistently
M. Hislop, New species from the Leucopogon pulchellus group
89
hairy adaxial surface which is always noticeably more densely hairy than the abaxial. The taxonomic
significance of a relatively dense indumentum on the upper leaf surface of the kind seen in L. decrescens
is discussed elsewhere (Hislop 2009b).
There is little to distinguish between the two species in terms of their floral morphologies, but whereas
the flowers of L. decrescens almost always have hairy ovaries, in L. polymorphus they may be glabrous
or hairy. The latter is unusual in the L. pulchellus group (and the genus as a whole) in that hairy or
glabrous ovaries are more or less equally common. There is also at least a partial difference between
the two species in the shape of the drupe. In L. polymorphus it is never more than obscurely angular in
section but in L. decrescens the angularity may be quite pronounced. As discussed below L. decrescens
is a variable species in regard to a number of characters and that includes the often significant one of
fruit shape. The two species have allopatric distributions with L. polymorphus occurring mostly on
the coastal plain from the Yalgorup-Waroona area north to near Leeman.
Although L. pulchellus is another very variable species it can always be distinguished from L. decrescens
by the presence of a keel on the distal abaxial leaf surface, the usually flat or plano-convex leaves and
the mostly glabrous ovaries. The consistently hairy adaxial leaf surface of L. decrescens provides another
point of difference between the two species. Leucopogon gracillimus DC. bears some resemblance to
those variants of L. decrescens with narrow leaves, and members of the L. obtusatus complex could
be mistaken for those that have relatively short leaves. In both cases their glabrous, 3-locular ovaries
will almost always distinguish them. Examples of sympatry in the L. pulchellus group are noteworthy
and L. decrescens (M. Hislop 4071) was found growing in close proximity to L. gracillimus s. lat.
(M. Hislop 4070) at a site west of Rocky Gully, where both species were locally common. Although
the granitic substrate made it an unusual habitat for L. decrescens, the plants were typical of that
species in all respects. There was no evidence of intergradation at the site.
Notes. As circumscribed here L. decrescens is a variable species, most obviously in leaf characters,
and some of this variation has a geographical basis. The current specimen base suggests that there is
a slight disjunction in the distribution of the species with a western population node in the valleys of
the Whicher Range and a larger eastern node beginning 60 or 70 km to the east. In general plants from
the western node tend to have smaller leaves which are glabrous, or at least less hairy, on their abaxial
surface relative to those from the east. Also the leaf margins in the western form have very short,
stiff hairs compared to the obviously ciliate margins of the type form. In addition a couple of western
collections (e.g. L.W. Sage & A.E. Raudino 2376) are aberrant in regard to an often significant taxonomic
character, having ovaries that are glabrous and 3-locular rather than hairy and 4- or 5-locular. Neither
glabrous nor 3-locular ovaries were recorded from the eastern collections examined during this study.
Although there may therefore appear to be some grounds for the recognition of a second taxon, the
overall pattern of variation across the species’ range suggests that a broad circumscription is more
appropriate, at least until further studies can be undertaken. Within the eastern node itself, there is
considerable morphological variation. While the leaves are usually larger than those of the western
node, occasional smaller-leaved populations do occur (see M. Hislop 4069). In their foliar character
these differ from the western form only in having clearly ciliate margins as described above. In terms
of potential difference in floral measurements there is more variation within the eastern node than
between the two nodes.
Further targeted collections are needed to assess the significance of differences in the angularity
of the fruit. Only one fruiting collection of the western form has been examined (M. Hislop 3684)
and that was found to have obscurely angular drupes. Of the five fruiting collections from eastern
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populations, three are distinctly angular and two have drupes comparable to Hislop 3684. However
it may be significant that the latter were collected towards the western end of the eastern population
node. Fruit of the type form is of the distinctly angular kind. In regard to the glabrous ovaries recorded
in a couple of the western collections, although the presence of an ovarian indumentum is certainly
taxonomically significant in Group C, there is reason to believe (as discussed above under general
notes on the morphology of the group) that it may never be an absolutely consistent character for any
species. Similarly, while locule number is undoubtedly an important character across Leucopogon
s. str., it is rather less reliable in the L. pulchellus group than in the other groups.
Leucopogon subsejunctus Hislop, sp. nov.
Typus: south-west of Darkan, Western Australia [precise locality withheld for conservation reasons],
13 November 2009, M. Hislop 3962 (holo: PERTH 08260214; iso: CANB, MEL, NSW).
Leucopogon sp. Darkan (R.S. Smith BNC 1047), Western Australian Herbarium, in FloraBase, http://
florabase.dpaw.wa.gov.au [accessed 11 April 2014].
Erect shrubs to c. 80 cm high and 80 cm wide, single-stemmed at ground level with a fire-sensitive
rootstock. Young branchlets with a moderately dense to dense indumentum of straight, patent hairs
to c. 0.1 mm long. Leaves helically arranged, variously antrorse, mostly narrowly ovate or narrowly
elliptic, less often ovate, elliptic or narrowly obovate, 3.0–8.5 mm long, 1.0–2.5 mm wide; apex
obtuse to acute; base attenuate to cuneate; petiole moderately well defined, 0.2–0.6 mm long, glabrous
on abaxial surface, hairy on adaxial surface and margins; lamina 0.25–0.40 mm thick, usually flat
or slightly concave adaxially, less often slightly convex, straight or more frequently recurved along
the longitudinal axis; surfaces discolorous, shiny; adaxial surface usually glabrous or sparsely hairy
towards the base, rarely sparsely hairy throughout, the venation not or barely evident; abaxial surface
paler, glabrous, smooth to ± striate, often at least with a groove on either side of the midrib, with
5–7 primary veins, the midrib rather thicker than the others, usually produced into an obvious keel,
at least towards the apex; margins usually glabrous, less often minutely ciliolate with coarse hairs
to c. 0.05 mm long. Inflorescence erect, terminal and upper-axillary; axis 3–12 mm long with 3–11
flowers; axis indumentum of dense, patent hairs 0.08–0.12 mm long; flowers erect and sessile. Fertile
bracts narrowly ovate to ovate, subacute to acute. Bracteoles ovate, 1.5–2.0 mm long, 1.0–1.5 mm
wide, obtuse to acute, sharply keeled; abaxial surface glabrous or very shortly hairy; margins ciliolate.
Sepals ovate, 2.4–3.2 mm long, 1.3–1.5 mm wide, obtuse to subacute; abaxial surface glabrous or
shortly hairy in the upper half, central portion pale greyish green, usually suffused purple towards
the apex and in a submarginal band, becoming scarious towards the margins, venation rather obscure
with only the midrib usually evident; margins ciliolate with hairs 0.05–0.10 mm long. Corolla
tube white, campanulate or broadly campanulate, distinctly shorter than sepals, 1.2–1.5 mm long,
1.4–1.7 mm wide, glabrous externally and internally. Corolla lobes white, partially flushed pink,
or pink throughout, much longer than tube (ratio = 1.7–2.7: 1), widely spreading from the base and
recurved, 2.6–3.5 mm long, 0.8–1.0 mm wide at base, glabrous externally, densely bearded internally;
indumentum white, 0.8–1.0 mm long near apex. Anthers partially exserted from the tube (by c. 7/8 of
their length), 2.0–2.6 mm long, prominently recurved towards the apex; sterile tip conspicuous, white,
0.7–1.0 mm long. Filaments terete, 0.8–1.1 mm long, attached 1/2–2/3 above anther base, adnate to
tube just below the sinuses. Ovary globose or broadly obovoid, 0.5–0.7 mm long, 0.5–0.7 mm wide,
usually distinctly lobed, appressed hairy, the hairs sometimes short and sparse, 3–5-locular. Style
0.5–0.7 mm long, tapering ± smoothly from ovary apex, included within corolla tube; stigma not or
scarcely expanded. Nectary annular, 0.30–0.50 mm long, entire or shallowly lobed, glabrous. Fruit
much longer than calyx, 2.6–3.0 mm long, 1.7–2.3 mm wide, shortly cylindrical, ellipsoid or obovoid,
M. Hislop, New species from the Leucopogon pulchellus group
91
deeply lobed, with as many lobes as fertilised ovules, the lobes with short, spreading hairs, separated
by deep, narrow, longitudinal grooves; surface between the lobes and the style base descending steeply;
style persistent. (Figures 1E, 7)
Diagnostic characters. The deeply lobed fruit is the most important feature by which this species can
be distinguished from potentially confusing species within the L. pulchellus group. Other significant
characters are: leaves abaxially keeled in the upper half and hairy, 3–5-locular ovaries.
Other specimens examined. WESTERN AUSTRALIA: [localities withheld for conservation reasons]
22 Aug. 1994, V. Crowley DKN 559 (PERTH); 16 Aug. 1993, V. Crowley DKN 561 (PERTH); 29 Aug.
2009, M. Hislop 3913 (CANB, NSW, PERTH); 30 Aug. 2009, M. Hislop 3918 (CANB, MEL, NSW,
PERTH); 15 Nov. 2009, M. Hislop 3988 (CANB, PERTH); 6 Sep. 2010, M. Hislop 4061 (CANB,
PERTH); 6 Sep. 2010, M. Hislop 4062 (CANB, MEL, NSW, PERTH); 23 Oct. 2010, M. Hislop 4094
(CANB, NSW, PERTH); 23 Oct. 2010, M. Hislop 4095 (NSW, PERTH); 27 Sep. 2006, R.S. Smith
BNC 1047 (PERTH); 5 Sep. 1986, P.W. Trembath 44 (PERTH).
Distribution and habitat. Currently known from a small area near Darkan (Figure 3) in the Southern
Jarrah Forest bioregion (Department of the Environment, Water, Heritage and the Arts 2008). Grows
in Eucalyptus marginata-Corymbia calophylla woodland over lateritic soils.
Phenology. Flowers mostly between August and September. Mature fruit has been recorded for
October and November.
Etymology. From the Latin sub (somewhat, not completely) and sejunctus (disunited, separated), a
reference to the remarkable morphology of the mature fruit which is so deeply lobed that the individual
locules are almost completely separated from each other.
Conservation status. Department of Parks and Wildlife Conservation Codes for Western Australian
Flora: Priority Two (Smith 2013), as L. sp. Darkan (R.S. Smith BNC 1047). This species is known
from six populations, including one in a nature reserve and another in a conservation park. Although
usually locally common where it does occur, it appears to have a restricted distribution and is very
likely to be a short-range endemic.
Affinities. In its vegetative and floral morphology L. subsejunctus closely resembles some variants
of L. pulchellus. As currently accepted the latter is a very variable species and probably comprises
segregate taxa. In particular it shows remarkable variation in fruit morphology, both in terms of the
overall shape and transverse section of the drupe as well as the presence of an indumentum. However
L. subsejunctus differs from all variants of L. pulchellus in having a drupe (Figure 1E) that is so deeply
lobed as to closely resemble a schizocarp in, for example, the genera Diplopeltis Endl. (Sapindaceae)
or Heliotropium L. (Boraginaceae). Even in flowering collections of the species these ovarian lobes
can be discerned. This provides an aid to identification in the absence, at the flowering stage, of any
other characters by which it can effectively be separated from L. pulchellus s. lat. Populations of the
two species are known to occur within as little as 12 km of each other between Collie and Darkan.
Notes. A fruiting specimen has been chosen as type of this species because it is the fruit character that
in large part distinguishes it from the otherwise very similar L. pulchellus.
Nuytsia Vol. 24 (2014)
92
Figure 7. Leucopogon subsejunctus. Photograph of flowering branchlet from M. Hislop
4061. Scale bar = 2 cm.
Acknowledgements
I would like to thank the following people who assisted in the preparation of this paper: Barbara Rye
for suggestions that led to an improvement in clarity of the text, Skye Coffey for technical assistance,
Steve Dillon for generating the distribution map, Ellen Hickman for the fruit illustrations, Julia PercyBower for providing the specimen photographs, Fred and Jean Hort for systematically collecting
L. darlingensis across its range, and Kelly Shepherd for formatting the images to best effect. The
curators and staff at BM, K and MEL are also thanked for providing relevant type specimens on loan.
M. Hislop, New species from the Leucopogon pulchellus group
93
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